HondaCowboy82
Full Access Member
Just wondering if any of you have ever tried to put a 6-71,4-71, 8-71 supercharger on a 6.9 or a 7.3 ? if you have, please tell me what came of it, cuz i am considering trying it on my 86 6.9 :draw
On an IDI, that's not a good thing! With the stock compression ratio, there simply isn't enough space to shove in more than 10 psi consistently without risking breaking things (head gaskets, head bolts, pistons, etc). Head studs can help some, but I still wouldn't be too comfortable going above 15 psi or so with studs and fresh gaskets.bentwings said:On 350 to 400 cu in you should be able to get about 28 maybe 30 pounds of boost out of a good 6-71. You could go with an 8-71 and get about 10% more.
Did he lower the compression ratio as well? If he only used the truck as a puller, it would make sense...after getting the compression ratio down to the 17:1 range, you should be able to safely get more boost into the cylinders. That said, a 17:1 ratio 6.9l wouldn't make a great daily driver...there's a sound clip floating around of one of these being cold-started on a sunny summer's day using a fully-working glow plug setup AND ether, and the engine acted as though it were in sub-zero temperatures with non-functioning glow plugs. Ken (land_yaght {did I spell his handle right?}) did this with a 6.9l (in fact, the sound clip described above was of his truck), but IIRC he wound up scattering the bottom end when he tried to pull with it. Last I heard, he hadn't given up, though...RKOCH said:I think I have some around here. It was a pullin' machine.
The Warden said:Did he lower the compression ratio as well? If he only used the truck as a puller, it would make sense...after getting the compression ratio down to the 17:1 range, you should be able to safely get more boost into the cylinders. That said, a 17:1 ratio 6.9l wouldn't make a great daily driver...there's a sound clip floating around of one of these being cold-started on a sunny summer's day using a fully-working glow plug setup AND ether, and the engine acted as though it were in sub-zero temperatures with non-functioning glow plugs. Ken (land_yaght {did I spell his handle right?}) did this with a 6.9l (in fact, the sound clip described above was of his truck), but IIRC he wound up scattering the bottom end when he tried to pull with it. Last I heard, he hadn't given up, though...